In recent years, light-weighting and thinning of a display device, an illumination device, and a solar battery have been progressed from the viewpoint of transportation, storage, design, and the like. Further, continuous production has also been carried out to manufacture a film-shaped member to be used in those devices by a roll-to-roll process. For example, as a flexible material that may be subjected to processing or treatment by the roll-to-roll process, the use of a thin glass has been proposed (for example, Patent Literatures 1 and 2).
The thin glass is extremely fragile, resulting in a poor handling property. As a member to be used in the above-mentioned devices, for example, there has been proposed a flexible substrate enhanced in handling property by adhering a resin film onto a surface of the thin glass so as to reinforce the thin glass (for example, Patent Literature 3). However, it is extremely difficult to handle a thin glass alone as a material without breaking the thin glass throughout steps of manufacturing such a member as described above.